Michael Ferreira of Salem, N.H., is charged with murder in the September 1969 death of John McCabe, 15, of Tewksbury. The teen's body was found in a Lowell field.

Edward Allen Brown told the court he remembered Ferreira grabbing McCabe and throwing him into the car of a friend. Brown said Ferreira would not let McCabe out of the car because he wanted to "teach him a lesson" for flirting with a girl.

In opening statements, prosecutors argued John McCabe was kidnapped after leaving a dance and assaulted by three older teens after he flirted with the girlfriend of one of them.

Brown testified that Ferreira and friend Walter Shelley dragged McCabe out of the car, and tied his hands and ankles. He told the courtroom he remembered McCabe struggling on the ground. "He was crying... saying get off me and things like that," Brown said.

Brown said when they returned a short time later to check on McCabe, Ferreira and Walter Shelley came running back to the car. One of them said McCabe wasn't breathing.

Brown said Ferreira told the group they had to keep what happened to themselves, and threatened to kill anyone who said anything.

Defense attorney Eric Wilson said Brown's account is "a fabrication" and the story "doesn't fit the evidence."

The now 58-year-old Ferreira was arrested in April 2011. He has pleaded not guilty.

Lawyers for Boston Marathon bomber Dzkokhar Tsarnaev rested their case in his federal death penalty trial Tuesday after presenting a brief case aimed at showing his late older brother was the mastermind of the 2013 terror attack.